1. Field
This application generally relates to a low temperature rotary union, and, more specifically, to an extremely low temperature rotary union implemented in a seal module, which is used to supply coolant to a rotating wafer chuck.
2. Description of the Related Art
The push for smaller transistors has led to the need for shallower and higher quality semiconductor junctions. For example, modern complementary metal oxide semiconductor (CMOS) transistors require very shallow and abrupt source and drain junctions.
One approach to forming a shallower and higher quality junction involves amorphization of the semiconductor surface on one side of the junction. In particular, during ion implantation of the junction, one side of the junction is amorphized. The amorphization of the semiconductor surface can be increased by performing ion implantation with the semiconductor substrate at a lower temperature.
In one conventional approach, the wafer is cooled prior to performing ion implantation. One problem with this approach is that the temperature of the wafer, and thus the semiconductor substrate, will increase during ion implantation.